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A More General Theory of Static Approximations for Conjunctive Queries [article]

Pablo Barceló, Miguel Romero, Thomas Zeume
2019 arXiv   pre-print
a more general notion of approximation based on the symmetric difference of query results, are almost unexplored.  ...  Approximating a hard CQ by a query from such a fragment can thus allow for an efficient approximate evaluation.  ...  Then, in order to develop a robust theory of bounded generalized hypertreewidth static approximations for CQs, it is necessary to have a good understanding of all three notions.  ... 
arXiv:1904.00934v1 fatcat:dgkiyt3earb57hlg4ndofofe7i

A More General Theory of Static Approximations for Conjunctive Queries

Pablo Barceló, Miguel Romero, Thomas Zeume
Conjunctive query (CQ) evaluation is NP-complete, but becomes tractable for fragments of bounded hypertreewidth.  ...  ., those that return correct answers only) are well-understood, the dual notion of overapproximations that return complete (but not necessarily sound) answers, and also a more general notion of approximation  ...  I C D T 2 0 1 8 7:14 A More General Theory of Static Approximations for Conjunctive Queries Proof.  ... 

Special Issue on the 2018 International Conference on Database Theory

Benny Kimelfeld
2020 Theory of Computing Systems  
Theory of Static Approximations for Conjunctive Queries," by Pablo Barceló, Miguel Romero, and Thomas Zeume, considers the approach of overcoming the intrinsic complexity of conjunctive queries by replacing  ...  the query with a more efficient alternative that constitutes an approximation with theoretical guarantees.  ... 
doi:10.1007/s00224-020-09968-7 fatcat:3pic46fpkbfwxbv3cd7bwizlo4

Deriving Invariants by Algorithmic Learning, Decision Procedures, and Predicate Abstraction [chapter]

Yungbum Jung, Soonho Kong, Bow-Yaw Wang, Kwangkeun Yi
2010 Lecture Notes in Computer Science  
Given invariant approximations derived from pre-and post-conditions, our new technique exploits the flexibility in invariants by a simple randomized mechanism.  ...  The proposed technique is able to generate invariants for some Linux device drivers and SPEC2000 benchmarks in our experiments.  ...  also would like to thank Heejae Shin for implementing OCaml binding of Yices.  ... 
doi:10.1007/978-3-642-11319-2_15 fatcat:zdcqbxfnxncvphqzheiax2qhs4

Automatically inferring loop invariants via algorithmic learning

2014 Mathematical Structures in Computer Science  
Theoretically, this technique can find arbitrary first-order invariants (modulo a fixed set of atomic propositions and an underlying satisfiability modulo theories solver) in the form of the given template  ...  Our contribution is a simpler technique than the previous works yet with a reasonable derivation power.  ...  More precise approximations of ι and ι will improve the performance by reducing the number of iterations via increasing the number of resolvable queries.  ... 
doi:10.1017/s0960129513000078 fatcat:opbe2lm32jf5fpfbyd2dj72iia

Cost-based Optimization of Complex Scientific Queries

Ruslan Fomkin, Tore Risch
2007 International Conference on Scientific and Statistical Database Management  
We developed a cost model for aggregation operators and other functions used in such queries and show that it substantially improves performance.  ...  High energy physics scientists analyze large amounts of data looking for interesting events when particles collide. These analyses are easily expressed using complex queries that filter events.  ...  The domain predicate is generated by the FROM clause. This general query is a reference query for the rest of the paper.  ... 
doi:10.1109/ssdbm.2007.8 dblp:conf/ssdbm/FomkinR07 fatcat:544k6u6rjjhdlpw5m7n7jj23di

On the equivalence of the static and disjunctive well-founded semantics and its computation

Stefan Brass, Jürgen Dix, Ilkka Niemelä, Teodor C. Przymusinski
2001 Theoretical Computer Science  
Nevertheless, since the static semantics employs a much richer underlying language than the D-WFS semantics, in general, the two semantics are di erent.  ...  It also allows us to use a recently developed minimal model theorem prover for an e cient implementation of the two semantics. : S 0 3 0 4 -3 9 7 5 ( 0 0 ) 0 0 0 4 5 -1  ...  Acknowledgements We thank Alexander Bochman and several anonymous reviewers for their useful comments on parts of the paper.  ... 
doi:10.1016/s0304-3975(00)00045-1 fatcat:2dwyvrc5bngqjeze6xgwcgd464

Improving the Efficiency of Approximate Inference for Probabilistic Logical Models by means of Program Specialization [article]

Daan Fierens
2011 arXiv   pre-print
From a logic programming perspective, sampling boils down to repeatedly calling the same queries on a knowledge base composed of a static part and a dynamic part.  ...  We develop an algorithm that specializes the definitions of the query predicates with respect to the static part of the knowledge base.  ...  The essence of partial deduction is to exploit staticness of a subset of the arguments of queries.  ... 
arXiv:1112.5381v1 fatcat:ltnrjivn4fcijmnwd33obiobki


Jihad Boulos, Nilesh Dalvi, Bhushan Mandhani, Shobhit Mathur, Chris Re, Dan Suciu
2005 Proceedings of the 2005 ACM SIGMOD international conference on Management of data - SIGMOD '05  
Predicate Functions mDDL specifies the functions to be used for generating probabilities for approximate predicates.  ...  This enables it to return even more tuples, or adjust the probabilities of the tuples it returns. Each of them results in static probabilities.  ... 
doi:10.1145/1066157.1066277 dblp:conf/sigmod/BoulosDMMRS05 fatcat:7gqaqjbuk5cldfvqa6o3njrmka

Computer Aided Verification of Relational Models by Strategic Rewriting

Claudia Mónica Necco, José N. Oliveira, Joost Visser, Roberto Uzal
2017 Journal of Computer Science and Technology  
In particular, properties such as the simplicity or injectivity of relations are not statically enforced in operations such as database queries, state transitions, or composition of functional components  ...  Remarkably, static checking support in these areas fails to exploit the full semantic content of relations.  ...  Oliveira was funded by ERDF -European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the Portuguese Foundation for Science  ... 
doi:10.24215/16666038.17.e19 fatcat:jhkm4adjsvej5j7j3fweozzldu

Supporting Visual Queries on Medium-Sized Node–Link Diagrams

Colin Ware, Robert Bobrow
2005 Information Visualization  
For reasons of clarity, a typical node-link diagram statically displayed on paper or a computer screen contains fewer than 30 nodes.  ...  The results show that the interactive highlighting methods support rapid visual queries of nodes in close topological proximity to one another, even for the largest diagrams tested.  ...  Visual Queries  ... 
doi:10.1057/palgrave.ivs.9500090 fatcat:gkm2leeqxzabtcsvghklwmg4gy

Towards a Logical Analysis of Biochemical Pathways [chapter]

Patrick Doherty, Steve Kertes, Martin Magnusson, Andrzej Szalas
2004 Lecture Notes in Computer Science  
In this paper, we provide a logical model of biochemical pathways and show how abductive hypothesis generation may be used to provide additional information about incomplete pathways.  ...  Biochemical pathways or networks are generic representations used to model many different types of complex functional and physical interactions in biological systems.  ...  In the case of a query containing free variables, the result of the query is a list of substitutions for those variables that satisfy the query.  ... 
doi:10.1007/978-3-540-30227-8_55 fatcat:pt33xck3vbayldwqvilck6ys5m

Query Processing in Ontology-Based Peer-to-Peer Systems [chapter]

Heiner Stuckenschmidt, Frank van Harmelen, Fausto Giunchiglia
2005 Ontologies for Agents: Theory and Experiences  
We provide a formal model for such approximate query processing based on limited shared vocabularies between peers, and we show how the quality of the approximation can be adjusted in a gradual manner.  ...  The result is a flexible architecture for query-processing in heterogenous and dynamic environments, based on a formal foundation. We present the approach and discuss it on the basis of a case study.  ...  for theory approximation.  ... 
doi:10.1007/3-7643-7361-x_7 fatcat:v5dohg4x4vc47m3cucptswbyci

Benchmarking Approximate Consistent Query Answering

Marco Calautti, Marco Console, Andreas Pieris
2021 Proceedings of the 40th ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems  
Although CQA provides a clean framework for querying inconsistent databases, it is arguably more informative to compute the percentage of repairs in which a candidate answer is true, instead of simply  ...  On the other hand, for practically relevant settings such as conjunctive queries and primary keys, there are data-efficient randomized approximation schemes for approximating this percentage.  ...  D STATIC QUERY GENERATOR To generate our stress test queries we exploit a recent query generator [3] , which we call static query generator (SQG).  ... 
doi:10.1145/3452021.3458309 fatcat:huu3d2ncurbsxjgpybg6jhzusa

Front Matter, Table of Contents, Preface, Conference Organization

Benny Kimelfeld, Yael Amsterdamer, Marc Herbstritt
2018 International Conference on Database Theory  
Mikaël Monet, and Pierre Senellart . . . . . . . . . . . . . . . . . . . . . . . . . . . 6:1-6:17 A More General Theory of Static Approximations for Conjunctive Queries Pablo Barceló, Miguel Romero, and  ...  0:iii LIPIcs -Leibniz International Proceedings in Informatics LIPIcs is a series of high-quality conference proceedings across all fields in informatics.  ...  the "where" and "why" flavors of provenance in a unified, application independent framework, using a general-purpose semi-structured data model.  ... 
doi:10.4230/lipics.icdt.2018.0 dblp:conf/icdt/X18 fatcat:ch2txo7nqjhthml4nlh4jkgakm
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